porpoising is caused by the engine lifting the nose of the boat out of the water until it is no longer supported and drops down again. The engine power then lifts the bows up and the cycle repeats itself. Lots of boats can be made to do it, not just warped V designs. Richard is right however the problem is easily cured by changing the trim slightly, or moving something heavy around the boat, normally a chuffin great fat diver and his kit.

Thanks guys for the info re Scorpion. My friend has quite a few bits in the bow locker (which I may add has suspension things to keep it up and make lifting it easier -- WOW what a luxury!!)

May be the engine is set up the wrong way or has a lot of weight aft. But it definitely was going up and down not so much on the chop (well it did but possibly was the waves too) but on the flat. It did this in all states of trim settings up down, middle. Very strange, but overall very nice LARGE (is the operative word) RIB. Pity is so expensive

Re Ballistic I think that is not as expenssive as they sell it in the UK

My opinion for what it's worth is as this. Please bear in mind that I am no expert, that I have no money invested in either boat and that my only experience of ribs is as a passenger and driver of a Ribtec 6.5 & Scorpion 8.1.

The Ribtec was a great boat, with excellent sea keeping abilities, upto about Force 6 or 7, but very wet!

The Scorpion is an in a different league alltogether, an awesome boat & very dry.

We have been out in some very heavy seas in the Scorpion this year - in particular off the coast of France a few months ago - and it was superb.

I had put most of this down to the differnce in size, however a trip to Plymouth in fairly moderate seas in the company of another (larger) Rib this weekend put it into perspective. We had to slow down a wait for the other boat to catch us up on numerous occasions. A combination of good hull design and, please don't underestimate this, good seating for the driver & crew won the day. He was uncomfortable above 30 Knts and we were uncomfortable below that.

The Scorpion can feel a little bow light at first, but as others have mentioned, trim it correctly and drive it at the speed it was designed to go and it all comes together.

At the end of the day it all comes down to money and if your budget allows I would say go for a Scorpion. The build quuality is fantastic and you should get a good price when you come to sell.